European Space Agency to launch exoplanet-spotter

The European Space Agency (ESA) has selected a project called Cheops – short for CHaracterising ExOPlanets Satellite – as the winner of its new process for choosing fast, cheap, space missions.

The agency issued its Call for Small Missions in March 2012. Cheops emerged triumphant over 25 other submissions.

The ESA says “Cheops will operate in a Sun-synchronous low-Earth orbit at an altitude of 800 km” and is expected to operate for three-and-a-half years after its 2017 launch.

The satellite's job, as its name implies, will be exoplanet-hunting. The craft will do so by peering at solar systems known to house planets, the better to capture detailed data that will let humanity understand the composition of those worlds.

ESA hopes that by doing so we will gain a better understanding of exoplanets, while data will also be shared with terrestrial telescopes to help them continue exoplanet studies.

The decision to proceed with Cheops is timely, as the Kepler spacecraft currently employed as humanity's premier planet-spotter suffered the loss of one of its reaction wheels in July 2012. Reaction wheels are used to aim the spacecraft's instruments and while Kepler started out with four, it needs three to operate. The mission's intended life was three-and-a-half years, but as it was launched in March 2009 the craft's expected working lifespan has been achieved.

Funding has been secured to operate Kepler until 2016, but if another reaction wheel fails that effort will be futile.

If the ageing spacecraft can be nursed into 2016, Cheops will take over a little later, meaning only a small gap in humanity's space-based exoplanet-spotting regime. ®